Somewhat of a rant but I think people are always too quick to talk about Leagues "folding" because such and such player may not play there. It's like when people say CHL teams would "fold" if all the 19 year olds got raided to the AHL? Why? It doesn't make sense. No more sense than saying AHL teams are going to fold because their best players get called up to the NHL. People may go because it's affordable entertainment, not because it's the best players in the world.
In 1980-81, there were 12 OHL teams, 13 WHL teams and 10 QMJHL teams. That's 35 teams across the Leagues that make up the CHL. The NHL's demographics were 81.4 % Canadian (524 players in total) on a Games Played basis. 16/21 1st Round Picks in the 1981 Draft played in one of these leagues.
In 2023-24, the NHL's demographics were 42.4 % Canadian on a Games Played Basis, which is nearly halved. The total number of Canadians to play in at least 1 NHL game that season were 434, which is 90 fewer than 1980-81 even as eleven new teams (and 11 * 20 lineup spots on a given night) were added into the league. At the same time, at the Junior Hockey level, you had 20 OHL teams, 22 WHL teams, and 18 QMJHL teams. That's 60 teams across the Leagues that make up the CHL.
Despite whatever diluting effect that creates as pathways outside the CHL became more common to reach the NHL while the number of CHL teams expanded, these Leagues did not die or suffer financial catastrophe. Because a sporting league's viability isn't tied to its perceived feeder impact on the Pro League or an arm's race for the "best" talent.
What leagues "survive" just depends on the ability to sustain costs for whatever the league represents and the demand amongst players for such a league. There's all sorts of Junior Leagues that have no zeitgeist relevance because they can get by with players paying their own fees to participate in the League.... Generally if one League goes away, something else with a new name and maybe new people at whatever functions for a league office will fill its place, because it's all largely demand driven from the player pool at the end of the day.
The pool of kids wanting to play junior hockey doesn't change too much based on any decision. It's mostly just going to be a shuffling around. Maybe more kids not on "the path" anymore will call it quits earlier, but a lot will keep playing for as long as viable until they become real adults that need to get a job. But think through it, if QMJHL teams raid BCHL teams... that means a spot on the QMJHL roster was taken away from somebody else. So now if that player doesn't just quit, they have to go somewhere else. Maybe down to a local Junior A, and then that local Junior A player who lost their lineup spot either quits or goes somewhere else, and so and on so forth.